Hypercarnivore

A hypercarnivore is an animal that exclusively eats meat and nothing else. [cite journal|doi=10.1666/0094-8373(2004)0300108:EOHTEO2.0.CO;2|title=Evolution of hypercarnivory: the effect of specialization on morphological and taxonomic diversity|year=2004|author=Holliday, J.A and S.J. Steppan|journal=Paleobiology|volume=30|issue=1|pages=108-128] The word "carnivore" can refer to species of the mammalian order Carnivora, but it is more generally used to refer to animals that consume meat. Many species in the order Carnivora are not hypercarnivores. For example, bears (order Carnivora, family Ursidae) forage widely on plant material. Many animals outside of the order Carnivora can be considered hypercarnivores. Such examples include dolphins, eagles, snakes, marlin, most sharks, and such invertebrates as octopuses.

Hypercarnivores need not be superpredators. Salmon are exclusively carnivorous, yet they are prey at all stages of life for a variety of organisms.

Many prehistoric mammals of the clade Carnivoramorpha (Carnivora and Miacoidea without Creodonta), along with the early Order Creodonta, and some mammals of the even earlier Order Cimolesta, were hypercarnivores. The earliest carnivorous mammal is considered to be the "Cimolestes" that existed during the Late Cretaceous and Tertiary Periods in North America about 65 million years ago. Theropod dinosaurs such as "Tyrannosaurus rex" that existed during the late Cretaceous, although not mammals, were obligate carnivores.

Large hypercarnivores evolved frequently in the fossil record, often in response to an ecological opportunity afforded by the decline or extinction of previously dominant hypercarnivorous taxa. While the evolution of large size and carnivory may be favored at the individual level, it can lead to a macroevolutionary decline, wherein such extreme dietary specialization results in reduced population densities and a greater vulnerability for extinction. [cite doi|10.1126/science.1102417] As a result of these opposing forces, the fossil record of carnivores is dominated by successive clades of hypercarnivores that diversify and decline, only to be replaced by new hypercarnivorous clades.

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